Highly circularly polarized monochromatic high harmonic pulses via a reflective phase retarder at 27.9 eV.

A circularly polarized (CP) single-order high harmonic pulse light source, operating at a photon energy of 27.9 eV, is developed. The production of CP harmonic pulses with a degree of polarization exceeding 99% is achieved by utilizing a high-throughput phase retarder composed of SiC mirrors.

Skin stiffness determined from occlusion of a horizontally running microvessel in response to skin surface pressure: a finite element study of sacral pressure ulcers.

Pressure ulcers occur following sustained occlusion of microvessels at bony prominences under skin surface pressure (SSP). However, the mechanical conditions of the surrounding soft tissue leading to microvascular occlusion are not fully understood. This study determined the stiffness of homogenized skin with microvasculature at the sacrum that occludes microvessels at an SSP of 10 kPa (consistent with a standard mattress) and recovers from occlusion at 5 kPa (consistent with a pressure-redistribution mattress).